If you don't want your spouse to find out what you're doing, you shouldn't be doing it.
I've been giving this a lot of thought lately. From women hiding secret credit cards from their husbands, to husbands chatting up the cute girl at work. Whatever it is. If you're doing something that you don't want your spouse to know about, you need to stop. Your spouse is your other half. Your partner in life. Should be your best friend and your most trusted confidante. If you don't want them to know what you're doing, then it's a pretty safe bet that you shouldn't be doing it. Period.